Nanothermochromic diffraction gratings with giant switching contrast based on the metal-insulator transition of vanadium dioxide

摘要

Nanothermochromic diffraction gratings based on the metal-insulator transition of VO_2 are fabricated by site-selective ion-beam implantation in a SiO_2 matrix. The studied diffraction gratings were defined (ⅰ) directly by spatially selective ion-beam synthesis or (ⅱ) by site-selective deactivation of the metal-insulator transition by ion-beam induced structural defects. The strongest increase of the diffraction efficient was observed at a wavelength of 1550 nm exceeding one order of magnitude for the selectively deactivated gratings. The observed pronounced thermal hysteresis extends down close to room temperature and makes these optical elements well suited for optical memory devices.